HARTFORD, Conn. — Chronic wasting disease in deer, a fatal and contagious neurological disease that has been called “the biggest threat to deer hunting,” is quickly spreading across the United States. Though the disease has been found as close as New York, no confirmed cases have appeared in Connecticut, according to officials. The disease is affecting deer nationwide and is spreading across ...

Chronic wasting disease in recent years has threatened wild deer around the country.

David Joles/Minneapolis Star Tribune/TNS

HARTFORD, Conn. — Chronic wasting disease in deer, a fatal and contagious neurological disease that has been called “the biggest threat to deer hunting,” is quickly spreading across the United States. Though the disease has been found as close as New York, no confirmed cases have appeared in Connecticut, according to officials.

The disease is affecting deer nationwide and is spreading across the country, according to Andrew Labonte, wildlife biologist and disease specialist with the state’s Department of Energy and Environmental Protection. As of this year, chronic wasting disease has been reported in 36 U.S. states. The disease has been detected in both free-ranging and captive deer, elk and moose populations. There are no known cases of chronic wasting disease in New England, but it has been detected in New York, Pennsylvania, and just recently in Delaware.

“It’s a growing problem across the country, but it’s not yet been detected here,” Labonte said. “We have been testing for it since 2003, collecting anywhere from a couple hundred samples to over 400 samples per year. At this point, we have collected over 10,000 samples that have all been negative. These have all been opportunistic samples from taxidermists. We pay them around $5 per sample. Most of the hunters don’t even realize that deer they have taxidermy is tested for CWD.”

Chronic wasting disease is a fatal disease of the brain and nervous system that affects several species and is caused by infectious, misfolded proteins called prions, according to Labonte. The prions are spread between animals through bodily fluids, including saliva, blood, urine and feces, and can occur through direct contact or indirectly through contamination of soil, food or water. Currently, no treatments or vaccines are available, officials said.

Labonte said the state sends out samples to get tested each May. This year, around 400 deer will be tested.

The disease in deer is often characterized by progressive weight loss, stumbling, lack of coordination, listlessness, drooping ears, excessive drooling or thirst and a lack of fear of humans. The disease often takes 12 to 18 months before symptoms start to appear, making it difficult to spot deer with the disease early on. In late-stage chronic wasting disease, deer often appear emaciated and gaunt, Labonte said. The only way to positively identify chronic wasting disease in deer is through laboratory testing of deer lymph node or brain stem tissue.

“Anybody who sees a deer behaving or acting strange, or a deer that looks emaciated, should report that to DEEP,” Labonte said. “Most of the time, it turns out to be a deer infected with rabies or with Hemorrhagic disease. Those are the two fatal diseases we find affecting deer in Connecticut.”

Labonte said that the state sends brain matter collected from all taxidermy deers to a lab in Pennsylvania. So far, the state has not had one positive case since testing began in 2003. Scientists say that chronic wasting disease started on a captive deer farm in Colorado in 1967 and has since spread rapidly, according to the U.S. Centers for Disease Control and Prevention. One theory for how the disease is spread is through captive cervid farms that house deer, elk, or moose in large quantities. Those infected deer can then transmit it to wild deer they come in contact with.

“One of the main reasons why New England does not have CWD is that we don’t have a large captive cervid industry,” Labonte said. “In Connecticut, we only have a couple captive cervid farms but they are relatively small. They are mostly mom and pop type of establishments for personal satisfaction and not for hunting or meat persons. One family in Connecticut has 10 or more deer. But again, this is very small compared to other states. In Pennsylvania and New York, there are farms with thousands of cervid species. It is believed those establishments are the contributors to CWD.”

Labonte said Connecticut has strict policies and protocols in place to ensure chronic wasting disease is not brought into the state’s borders. The state has a mandatory ban on importing high-risk deer parts from CWD-positive states like Pennsylvania or New York, prohibiting natural urine-based lures, and recommending safe carcass handling procedures, he said.

“Hunters themselves are going to be the main source of introduction of CWD at this point,” Labonte said. “This past year, we had a couple hunters harvest deer in Pennsylvania and brought it back to Connecticut to be butchered. That is illegal and has been for a long time now. No hunter can bring a deer from a CWD state into Connecticut. Luckily, the hunters brought the deer to a butcher who then informed EnCon police. We do take CWD very seriously and remind hunters to never bring a deer carcass from a known CWD positive state into Connecticut.”

Most states now have laws and policies to thwart the spread of chronic wasting disease, Labonte said. New York has implemented a strict policy that no deer carcasses can be brought into the state, despite whether it was shot in a chronic wasting disease positive state or not. Other states are adopting similar bans and laws against outside harvesting.

Although there is no known transmission to humans, the CDC recommends hunters who harvest deer, including white-tailed, red, sika, or mule, elk or moose from an area where chronic wasting disease has been confirmed, to have their animals tested before consuming the meat. Meat from an animal that tests positive should not be eaten.

“To date, there is no strong evidence that CWD infects people, but these studies show that caution and additional research are warranted. Scientists are conducting studies to learn more about the potential risk to people who hunt or eat deer or elk meat, for example, by determining if they are diagnosed with prion diseases more often than people who do not. Since it may take years to decades for symptoms to appear, we won’t know the results for some time,” the CDC said in a statement.

In states with chronic wasting disease, Labonte said hunters often will bag their deer and then get it tested before consuming it. Because the disease is considered “the biggest threat to the future of deer hunting” by several hunting and conservation groups, federal dollars are being spent to try and curb its spread.

The Theodore Roosevelt Conservation Partnership, a group dedicated to hunters and fisherman, helped develop and pass the Chronic Wasting Disease Research and Management Act, which authorizes an annual $70 million investment through 2028 to fund research aimed at curbing the spread of the disease. The conservation group said that thousands of hunters across the U.S. participated in signing petitions and lobbying congress for the funding.

“We do have a lot of people from Connecticut who hunt in Pennsylvania and New York,” Labonte said. “We want to remind hunters that they cannot bring those deer carcasses back to Connecticut. The deer must be completely butchered and de-boned before it can be brought into the state. The deer could be contaminated with CWD, and if discarded incorrectly, can spread the disease. We want to remind hunters to remain vigilant and follow the law.”